package ifreecomm.nettydemo.netty;

/**
 * Created by wang on 2019/1/8.
 */

public class BytesConvertUtils {

    /**
     * /long类型转成byte数组
     *
     * @param number
     * @return
     */
    public static byte[] longToByte(long number) {
        long temp = number;
        byte[] b = new byte[8];
        for (int i = 0; i < b.length; i++) {
            b[i] = new Long(temp & 0xff).byteValue();
            //将最低位保存在最低位
            temp = temp >> 8; // 向右移8位
        }
        return b;
    }

    /**
     * byte数组转成long
     * @param b
     * @return
     */
    public static long byteToLong(byte[] b) {
        long s = 0;
        long s0 = b[0] & 0xff;// 最低位
        long s1 = b[1] & 0xff;
        long s2 = b[2] & 0xff;
        long s3 = b[3] & 0xff;
        long s4 = b[4] & 0xff;// 最低位
        long s5 = b[5] & 0xff;
        long s6 = b[6] & 0xff;
        long s7 = b[7] & 0xff;

        // s0不变
        s1 <<= 8;
        s2 <<= 16;
        s3 <<= 24;
        s4 <<= 8 * 4;
        s5 <<= 8 * 5;
        s6 <<= 8 * 6;
        s7 <<= 8 * 7;
        s = s0 | s1 | s2 | s3 | s4 | s5 | s6 | s7;
        return s;
    }

    /**
     * int到字节数组的转换！
     *
     * @param number
     * @return
     */
    public static byte[] intToByte(int number) {
        int temp = number;
        byte[] b = new byte[4];
        for (int i = 0; i < b.length; i++) {
            b[i] = new Integer(temp & 0xff).byteValue();
            //             将最低位保存在最低位
            temp = temp >> 8; // 向右移8位
        }
        return b;
    }

    /**
     * 注释：字节数组到int的转换！
     *
     * @param b
     * @return
     */
    public static int byteToInt(byte[] b) {
        int s = 0;
        int s0 = b[0] & 0xff;// 最低位
        int s1 = b[1] & 0xff;
        int s2 = b[2] & 0xff;
        int s3 = b[3] & 0xff;
        s3 <<= 24;
        s2 <<= 16;
        s1 <<= 8;
        s = s0 | s1 | s2 | s3;
        return s;
    }

    public static int bytes2int(byte[] b) {

//byte[] b=new byte[]{1,2,3,4};

        int mask = 0xff;

        int temp = 0;

        int res = 0;

        for (int i = 0; i < 4; i++) {

            res <<= 8;

            temp = b[i] & mask;

            res |= temp;

        }

        return res;

    }

    /**
     * 注释：short到字节数组的转换！
     *
     * @param number
     * @return
     */
    public static byte[] shortToBytes(short number) {
        int temp = number;
        byte[] b = new byte[2];
        for (int i = 0; i < b.length; i++) {
            b[i] = new Integer(temp & 0xff).byteValue();
            //             将最低位保存在最低位
            temp = temp >> 8; // 向右移8位
        }
        return b;
    }

    /**
     * 注释：字节数组到short的转换！
     *
     * @param b
     * @return
     */
    public static short bytesToShort(byte[] b) {
        short s = 0;
        short s0 = (short) (b[0] & 0xff);// 最低位
        short s1 = (short) (b[1] & 0xff);
        s1 <<= 8;
        s = (short) (s0 | s1);
        return s;
    }
}
